A Possible Mechanism for Electron‐Bombardment‐Induced Loop Punching in Helium‐Implanted Materials

S. E. Donnelly, A. A. Lucas, Ph Lambin, J. P. Vigneron

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3 Citations (Scopus)


The recently proposed mechanism for the punching of dislocation loops by overpressurized helium bubbles in molybdenum is studied quantitatively. According to this mechanism, under the electron beam of the transmission microscope, He atoms are excited or ionized and the resulting excited species (excited He atoms and free electrons) are responsible for the pressure rise in the gas beyond the threshold for loop punching. In the model, the pressure increase is attributed to EL reduction of the effective volume accessible to the gas due to the formation of a cavity around each excited species. The radius of this cavity is evaluated and, also, the excited fraction required to reach the threshold is discussed in terms of excitation life times.

Original languageEnglish
Pages (from-to)543-548
Number of pages6
Journalphysica status solidi (a)
Issue number2
Publication statusPublished - 16 Oct 1983
Externally publishedYes


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